//////////////////////////////////////////////////////////////////////////////////////////////////
// 
// File: ps_multitex.cpp
// 
// Author: Frank Luna (C) All Rights Reserved
//
// System: AMD Athlon 1800+ XP, 512 DDR, Geforce 3, Windows XP, MSVC++ 7.0 
//
// Desc: Deomstrates multi-texturing using a pixel shader.  You will have
//       to switch to the REF device to run this sample if your hardware
//       doesn't support pixel shaders.
//          
//////////////////////////////////////////////////////////////////////////////////////////////////

#include "d3dUtility.h"

//
// Globals
//

IDirect3DDevice9* Device = 0; 

const int Width  = 640;
const int Height = 480;

IDirect3DPixelShader9* MultiTexPS = 0;
ID3DXConstantTable* MultiTexCT    = 0;

IDirect3DVertexBuffer9* QuadVB = 0;

IDirect3DTexture9* BaseTex      = 0;
IDirect3DTexture9* SpotLightTex = 0;
IDirect3DTexture9* StringTex    = 0;

D3DXHANDLE BaseTexHandle      = 0;
D3DXHANDLE SpotLightTexHandle = 0;
D3DXHANDLE StringTexHandle    = 0;

D3DXCONSTANT_DESC BaseTexDesc;
D3DXCONSTANT_DESC SpotLightTexDesc;
D3DXCONSTANT_DESC StringTexDesc;

// 
// Structs
//

struct MultiTexVertex
{
	MultiTexVertex(float x, float y, float z,
		float u0, float v0,
		float u1, float v1,
		float u2, float v2)
	{
		 _x =  x;  _y =  y; _z = z;
		_u0 = u0; _v0 = v0; 
		_u1 = u1; _v1 = v1;
		_u2 = u2, _v2 = v2;
	}

	float _x, _y, _z;
	float _u0, _v0;
	float _u1, _v1;
	float _u2, _v2;

	static const DWORD FVF;
};
const DWORD MultiTexVertex::FVF = D3DFVF_XYZ | D3DFVF_TEX3; 

//
// Framework functions
//
bool Setup()
{
	HRESULT hr = 0;

	//
	// Create geometry.
	//

	Device->CreateVertexBuffer(
		6 * sizeof(MultiTexVertex), 
		D3DUSAGE_WRITEONLY,
		MultiTexVertex::FVF,
		D3DPOOL_MANAGED,
		&QuadVB,
		0);

	MultiTexVertex* v = 0;
	QuadVB->Lock(0, 0, (void**)&v, 0);

	v[0] = MultiTexVertex(-10.0f, -10.0f, 5.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f);
	v[1] = MultiTexVertex(-10.0f,  10.0f, 5.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f);
	v[2] = MultiTexVertex( 10.0f,  10.0f, 5.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f);

	v[3] = MultiTexVertex(-10.0f, -10.0f, 5.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f);
	v[4] = MultiTexVertex( 10.0f,  10.0f, 5.0f, 1.0f, 0.0f, 1.0f, 0.0f, 1.0f, 0.0f);
	v[5] = MultiTexVertex( 10.0f, -10.0f, 5.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f);

	QuadVB->Unlock();

	//
	// Compile shader
	//

	ID3DXBuffer* shader      = 0;
	ID3DXBuffer* errorBuffer = 0;

	hr = D3DXCompileShaderFromFile(
		"ps_multitex.txt",
		0,
		0,
		"Main", // entry point function name
		"ps_1_1",
		D3DXSHADER_DEBUG, 
		&shader,
		&errorBuffer,
		&MultiTexCT);

	// output any error messages
	if( errorBuffer )
	{
		::MessageBox(0, (char*)errorBuffer->GetBufferPointer(), 0, 0);
		d3d::Release<ID3DXBuffer*>(errorBuffer);
	}

	if(FAILED(hr))
	{
		::MessageBox(0, "D3DXCompileShaderFromFile() - FAILED", 0, 0);
		return false;
	}

	//
	// Create Pixel Shader
	//
	hr = Device->CreatePixelShader(
		(DWORD*)shader->GetBufferPointer(),
		&MultiTexPS);

	if(FAILED(hr))
	{
		::MessageBox(0, "CreateVertexShader - FAILED", 0, 0);
		return false;
	}

	d3d::Release<ID3DXBuffer*>(shader);

	//
	// Load textures.
	//

	D3DXCreateTextureFromFile(Device, "crate.bmp", &BaseTex);
	D3DXCreateTextureFromFile(Device, "spotlight.bmp", &SpotLightTex);
	D3DXCreateTextureFromFile(Device, "text.bmp", &StringTex);

	//
	// Set Projection Matrix
	//

	D3DXMATRIX P;
	D3DXMatrixPerspectiveFovLH(
			&P,	D3DX_PI * 0.25f, 
			(float)Width / (float)Height, 1.0f, 1000.0f);

	Device->SetTransform(D3DTS_PROJECTION, &P);

	//
	// Disable lighting.
	//

	Device->SetRenderState(D3DRS_LIGHTING, false);

	// 
	// Get Handles
	//

	BaseTexHandle      = MultiTexCT->GetConstantByName(0, "BaseTex");
	SpotLightTexHandle = MultiTexCT->GetConstantByName(0, "SpotLightTex");
	StringTexHandle    = MultiTexCT->GetConstantByName(0, "StringTex");

	//
	// Set constant descriptions:
	//

	UINT count;
	
	MultiTexCT->GetConstantDesc(BaseTexHandle,      &BaseTexDesc, &count);
	MultiTexCT->GetConstantDesc(SpotLightTexHandle, &SpotLightTexDesc, &count);
	MultiTexCT->GetConstantDesc(StringTexHandle,    &StringTexDesc, &count);

	MultiTexCT->SetDefaults(Device);

	return true;
}

void Cleanup()
{
	d3d::Release<IDirect3DVertexBuffer9*>(QuadVB);

	d3d::Release<IDirect3DTexture9*>(BaseTex);
	d3d::Release<IDirect3DTexture9*>(SpotLightTex);
	d3d::Release<IDirect3DTexture9*>(StringTex);

	d3d::Release<IDirect3DPixelShader9*>(MultiTexPS);
	d3d::Release<ID3DXConstantTable*>(MultiTexCT);
}

bool Display(float timeDelta)
{
	if( Device )
	{
		// 
		// Update the scene: Allow user to rotate around scene.
		//
		
		static float angle  = (3.0f * D3DX_PI) / 2.0f;
		static float radius = 20.0f;
		
		if( ::GetAsyncKeyState(VK_LEFT) & 0x8000f )
			angle -= 0.5f * timeDelta;

		if( ::GetAsyncKeyState(VK_RIGHT) & 0x8000f )
			angle += 0.5f * timeDelta;

		if( ::GetAsyncKeyState(VK_UP) & 0x8000f )
			radius -= 2.0f * timeDelta;

		if( ::GetAsyncKeyState(VK_DOWN) & 0x8000f )
			radius += 2.0f * timeDelta;

		D3DXVECTOR3 position( cosf(angle) * radius, 0.0f, sinf(angle) * radius );
		D3DXVECTOR3 target(0.0f, 0.0f, 0.0f);
		D3DXVECTOR3 up(0.0f, 1.0f, 0.0f);
		D3DXMATRIX V;
		D3DXMatrixLookAtLH(&V, &position, &target, &up);

		Device->SetTransform(D3DTS_VIEW, &V);
		
		//
		// Render
		//

		Device->Clear(0, 0, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0xffffffff, 1.0f, 0);
		Device->BeginScene();

		Device->SetPixelShader(MultiTexPS);
		Device->SetFVF(MultiTexVertex::FVF);
		Device->SetStreamSource(0, QuadVB, 0, sizeof(MultiTexVertex));

		// base tex
		Device->SetTexture(     BaseTexDesc.RegisterIndex, BaseTex);
		Device->SetSamplerState(BaseTexDesc.RegisterIndex, D3DSAMP_MAGFILTER, D3DTEXF_LINEAR);
		Device->SetSamplerState(BaseTexDesc.RegisterIndex, D3DSAMP_MINFILTER, D3DTEXF_LINEAR);
		Device->SetSamplerState(BaseTexDesc.RegisterIndex, D3DSAMP_MIPFILTER, D3DTEXF_LINEAR);

		// spotlight tex
		Device->SetTexture(     SpotLightTexDesc.RegisterIndex, SpotLightTex);
		Device->SetSamplerState(SpotLightTexDesc.RegisterIndex, D3DSAMP_MAGFILTER, D3DTEXF_LINEAR);
		Device->SetSamplerState(SpotLightTexDesc.RegisterIndex, D3DSAMP_MINFILTER, D3DTEXF_LINEAR);
		Device->SetSamplerState(SpotLightTexDesc.RegisterIndex, D3DSAMP_MIPFILTER, D3DTEXF_LINEAR);

		// string tex
		Device->SetTexture(     StringTexDesc.RegisterIndex, StringTex);
		Device->SetSamplerState(StringTexDesc.RegisterIndex, D3DSAMP_MAGFILTER, D3DTEXF_LINEAR);
		Device->SetSamplerState(StringTexDesc.RegisterIndex, D3DSAMP_MINFILTER, D3DTEXF_LINEAR);
		Device->SetSamplerState(StringTexDesc.RegisterIndex, D3DSAMP_MIPFILTER, D3DTEXF_LINEAR);

		Device->DrawPrimitive(D3DPT_TRIANGLELIST, 0, 2);
		
		Device->EndScene();
		Device->Present(0, 0, 0, 0);
	}
	return true;
}

//
// WndProc
//
LRESULT CALLBACK d3d::WndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
	switch( msg )
	{
	case WM_DESTROY:
		::PostQuitMessage(0);
		break;
		
	case WM_KEYDOWN:
		if( wParam == VK_ESCAPE )
			::DestroyWindow(hwnd);

		break;
	}
	return ::DefWindowProc(hwnd, msg, wParam, lParam);
}

//
// WinMain
//
int WINAPI WinMain(HINSTANCE hinstance,
				   HINSTANCE prevInstance, 
				   PSTR cmdLine,
				   int showCmd)
{
	if(!d3d::InitD3D(hinstance,
		Width, Height, true, D3DDEVTYPE_HAL, &Device))
	{
		::MessageBox(0, "InitD3D() - FAILED", 0, 0);
		return 0;
	}
		
	if(!Setup())
	{
		::MessageBox(0, "Setup() - FAILED", 0, 0);
		return 0;
	}

	d3d::EnterMsgLoop( Display );

	Cleanup();

	Device->Release();

	return 0;
}